Passionate lovers of poetry and music, they dedicated much of their leisure time to those elegant pursuits. They taught Europe the game of chess; they gave it its taste for works of fiction--romances and novels. In the graver domains of literature they took delight: they had many admirable compositions on such subjects as the instability of human greatness; the consequences of irreligion; the reverses of fortune; the origin, duration, and end of the world. Sometimes, not without surprise, we meet with ideas which we flatter ourselves have originated in our own times. Thus our modern doctrines of evolution and development were taught in their schools. In fact, they carried them much farther than we are disposed to do, extending them even to inorganic or mineral things. The fundamental principle of alchemy was the natural process of development of metalline bodies. "When common people," says Al-Khazini, writing in the twelfth century, "hear from natural philosophers that gold is a body which has attained to perfection of maturity, to the goal of completeness, they firmly believe that it is something which has gradually come to that perfection by passing through the forms of all other metallic bodies, so that its gold nature was originally lead, afterward it became tin, then brass, then silver, and finally reached the development of gold; not knowing that the natural philosophers mean, in saying this, only something like what they mean when they speak of man, and attribute to him a completeness and equilibrium in nature and constitution--not that man was once a bull, and was changed into an ass, and afterward into a horse, and after that into an ape, and finally became a man." CHAPTER V. CONFLICT RESPECTING THE NATURE OF THE SOUL.--DOCTRINE OF EMANATION AND ABSORPTION. European ideas respecting the soul.--It resembles the form of the body. Philosophical views of the Orientals.--The Vedic theology and Buddhism assert the doctrine of emanation and absorption.--It is advocated by Aristotle, who is followed by the Alexandrian school, and subsequently by the Jews and Arabians.--It is found in the writings of Erigena. Connection of this doctrine with the theory of conservation and correlation of force.--Parallel between the origin and destiny of the body and the soul.--The necessity of founding human on comparative psychology. Averroism, which is based on these facts, is brought into Christendom through Spain and Sicily. History of the repression of Averroism.--Revolt of Islam against it.--Antagonism of the Jewish synagogues.--Its destruction undertaken by the papacy.--Institution of the Inquisition in Spain.--Frightful persecutions and their results.--Expulsion of the Jews and Moors.--Overthrow of Averroism in Europe.--Decisive action of the late Vatican Council.